Fluid transmission joint



L. F. G. BUTLER ET AL FLUID TRANSMISSION JOINT Dec. 17, 1940.

Filed Jan. 12, 1940 2 Sheets-Sheet 1 I 4 5 fnuenl'rs D 17", 9 I F. BUTLER ET AL 2,225,547

FLUID TRANSMISSION JOINT Filed Jan. 12, 1940 2 Sheets-Sheet 2 Patented Dec. 17, 1940 PATENT OFFICE 2,225,547 FLU'ID TRANSMISSION JOINT Leonard Frederick George Butler and William Cordiner, Bristol, England, assignors to The 'Bristol Aeroplane Company Limited, Bristol,

England, a British company Application January 12, 1940, Serial No. 313,624 In Great Britain December 2, 1938 4 Claims.

This invention relates to fluid-transmission joints for conveying fluid between an outer part and a relatively rotatable inner part, such as a rotating shaft. The outer part is herein referred to as the fixed part although the invention is applicable generally where the two parts are capable of relative rotation. The object of the invention is to provide a transmission joint which shall accommodate and be unaffected by small endwise movement between the two parts.

According to the invention, a conduit for conveying fluid between an inner and outer part which are relatively rotatable comprises a section in its length capable of movement in a direction endwise of the conduit and I engaging adjacent sections in the length of the conduit by spherical seatings so as to be capable of universal tilting movements in relation thereto. 1

A fluid-transmission joint according to the invention preferably comprises spherical seatings carried respectively by the outer part and by a member carried by the inner part which member is restrained against rotation with the inner part, and an extensible coupling having spherical ends engaging respectively with the said seatings whereby a conduit for fluid may be provided from one spherical seating to the other through the said coupling.

The said coupling preferably comprises two tubes, one slidable in the other, each having a spherical end to engage one of the said seatings, and a compression spring within the inner tube to press the two tubes apart and thereby-press the spherical ends into engagement with the seating s.

The member aforesaid which is carried by the inner part and which carries one of the said spherical seatings is preferably constituted by a sleeve surrounding the inner part, which may be a shaft. In order to prevent the pressure of the spring aforesaid from adding materially to" the bearing pressure between the sleeve and the shaft, the said extensible coupling is preferably so disw posed that its thrust on the sleeve is tangential,

5 or approximately tangential, with respect .to the surface of the shaft. v

. To balance the tendency of the spring to retate the sleeve on the shaft, two oppositely directed extensible couplings may be provided, each forming part of a separate conduit both of which enter the sleeve. 1 a

A specific embodiment of the invention will now be described, by way of example, as applied to the supply of pressure liquid to the hydraulic mech- 55 anism of a variable-pitch airscrew by way of the discrepancies such as misalignment, tilting and interior of the airscrew shaft. In the accompanying drawings,

Figure 1 is a sectional elevation, taken onthe line l--l of- Figure ..3 showing a joint forconveying liquid to and fromathe interior of an airscrew a shaft for the purpose of actuating a hydraulic pitch-varying motor,

Figure 2 is a face view, to the same scale as Figure l, of the T-shaped member hereinafter described, I

Figure 3 is a section, on the line 3-3of Figure 1, being drawn to an enlarged scale, and

Figures 4 and 5 are sections on the lines 4-4,. and 55,respectively of Figure 3 to explain the shape of the lugs and sleeve hereinafterdescribed.

As shown in the drawings the airscrew-shaft l0 is carried in a main bearing II in a plate [2 which is flanged at I3 for connection by a set of bolts l4,

, !5 to a gear-casing l6 which is secured to the front cover (not shown) of the crank-case of an internal-combustion engine. The engine-shaft (not shown) carries a bevel-gear (not shown)" whichengages a plurality of planet-gears l1, one of which is shown in Figure 1, each planet being rotatable on a stub-axle l8 formed integrally with the airscrew-shaft l0. A tail-piece l9 extends, rearwardly from the airscrew-shaft to engage a bearing inthe engine-shaft whereby the airscrewshaftuis additionally supported in known man-. ner. The planets l1 engage a bevel-gear 20 which is non-rotatably mountedby means of 'a splined connection 2i on a ring 22 which is fastened to the gear-casing l6 by means of the bolts l4, IS. The airscrew-shaft is thus driven ,by the engine shaft at a reduced, speed inknown manner. A variable-pitch airscrew (not shown) is carried at the forward end of the airscrewshaft (the left-hand end as seen in Figure l) and it is necessary to provide two separate and continuous liquid-conduits from the enginecrankcase, or another fixed part, to the interior of the shaft l0.

Formed in the gear-casing it are two conduits 23, 24 leading to depressions 25, 26 in a boss 21'. which is normally closed by a plate 28. From the depressions 25, 26 conduits 29, 30 lead respectively into register with holes 3|, 32 in the flanged portion: ofthe ring 22. Secured to the gear-casing l6 by means'of the bolts l5 (seeespecially Figure 3) is a T-shaped member, 33 the middle portion of which is formed with passages 34, 35, plugged at their ends 36, 31 but communicating through lateral ports with the holes 3| and 32 respectively. The passages 34, 35 diverge at the inner end of the member 33 each opening into a concave The shaft I8 is 33 passes 46 and 4| which of the shaft.

shaft is a bush ternal grooves 43, by lands 45, 46, 41.

Immediately surrounding the 42 having, two continuous in- 44 (Figures 4 and 5) bou'nded The groove 43 registers with the radial hole 48 (Figure 1) and the groove 44' with the hole 4| (Figure 4).

rounded'by a sleeve 48 which continuous with the groove 43 in rality of ports The bush is surthe bush through a plu- 5| in the bush 42, and with a similar groove 52 which communicates with the the inner end into the groove groove 44 through a similar. set of ports 53.

The sleeve 48 is. formed integrally with two lugs 54, 55. The lug 54 is formed with an internal elbow-shaped passage 56 which opens at 49 (Figure 4) and at theouter ,end into a concave spherical seating 51' (Figure 3). It will be seen that, in Figure 3, thebush 42 and sleeve 48 are partly broken away to showthe groove 43, ports 5|, groove 49,'passage 56. In like manner the lug 55 is formed with -a passage58 which opens at its inner end to the groove'52 (Figure 5) and at its outer end into a concave spherical seating 59 (Figure 3).

It will be seen that the hole 40 in the shaft communicates with the spherical seating 59 by way of the groove 43 in the bush 42; the ports 5|, the groove '49 and the passage 56 and that the port 4| communicates in-like manner with the spherical seating 51 by way of the groove 44, the ports 53, the'groove 52 and the passage 58.

, The spherical seatings 51 and 39 are connected together by an'extensible coupling shown in section in Figure 3. The coupling comprises an outer. sleeve 60, having a convex spherical end 62 to inner tube 6| slidable within the sleeve 60 and having a spherical end 63 to co-operate with the seating 39. The end 62 is cut with a hole 64 which communicates with the passage 56 and the end 63 is cut with a similar hole 65 which communicates with the passage 35'. The two parts 60 and 6| are pressed apart by a compression spring 66. I

The spherical seatings 59 and 38 are interconnected. bya similar coupling comprising an outer sleeveGl, and aninner-tube 68 the sleeve and tube'being pressed apart by a compression spring not shown) similar to the spring 66.

.It' will be understood that the shaft l9 rotates but that the sleeve 48 is held against rotation by its connection through the couplings to the stationary T-shaped member 33. The bush 42 willrotate with the shaft I0, being fixed thereto by being clamped between a flange 80 and a nut Alternatively, the bush-42 could be arranged to rotate both with respect to the shaft and with respect to the sleeve 48.

. Hydraulic liquid for varying the pitch of the airscrew blades in one direction'is admitted to theconduit 23 from which it flows, in the manner already explained, and as shownby the arare relatively displaced angularly (Figure 3) and longitudinally (Figure 1) is formed with a internal groove 49, communicating co-operate with the seating 51 and an rows in Figure 3, to the spherical seating 38. The liquid passes through the extensible coupling to the spherical seating 59 through which it flows, in the manner already explained, to the port 40. Hydraulic liquid for varying the pitch of the blades in the other direction is admitted to the conduit24 through which it flows, in the manner already explained, to the spherical seating 39. The liquid passes through the extensible coupling to the seating 51 from which it flows, as shown by the arrows in Figure 3, to the port 4|. The liquid discharged by the hydraulic motor may be returned to the engine in different ways according to the type of air-screw. For

.. example, when liquid under pressure is admitted to the conduit 23, the liquid discharged by the hydraulic motor may flow back through the conduit 24. Liquid from the ports 4|] and 4| is constrained to follow separate paths to the hydraulic motor. For convenience of assembly the T-shaped member 53 may be located with respect to the gear casing by means of a pin 69 passing through an eye of the member 33 and engaging lugs (Figure 1) formed integrally on the sleeve 48. It will be seen that the lugs 54 and 55 on the sleeve 48 are short in their radial dimension and that the axes of the couplings 60, 61 are disposed approximately perpendicularly to the airscrewshaft radii on which they lie. Consequently the forces exerted by springs 66 tend to balance one another and there is little resultant increase in the bearing load between sleeve 48 and bush 42. -Relative movement between the sleeve 48 and the gear-casing IS with respect to the airscrew shaft in a direction longitudinally of the shaft axis isac'commodated by tilting'of the extensible couplings and consequent rotation of the spherical'face 62 in the seating 51, of the face 63 in the seatin 59 and of the corresponding parts of the members 61 and 68. Tilting move ments between the airscrew shaft and the fixed parts or slight relative translational movements of the shaft are'also accommodated by tilting of the extensible couplings in the appropriate direction. Any 'tilting'movemerits of either coupling will increase the length of path for the liquid between the two concave spherical seatings which are engaged by that coupling but the'coupling extends in that direction to maintain a liquid-tight joint at each end of it.

We claimi l. A fluid-transmission joint, between a. rotating shaft and an outer part, comprising a sleeve surrounding the shaft, two spherical seatings carried by the sleeve, two spherical seatings carried by the outer part and two spherical-ended extensible coupling-members each engaging at one end with a spherical seating on the sleeve and at the other end with a spherical seating on the outer part wherein the two coupling members areoppositely disposed each with its axis substantially tangential to the surface of the shaft. 7

2. In a fluid transmission connection, a rotary shaft having a radial fluid passage therein, a sta tionary fluid supply ring embracing the shaft the stationary ring, said stationary support having a fluid conduit therein opening through the coupling head thereof, and a lengthwise exten sible coupling member universally connected between said coupling heads for maintaining intercommunication between the support and the ring during any variable relations between the support and the ring on the shaft.

3. In a fluid transmission connection, a stationary support having fluid conduits therein, a shaft mounted to turn in the support, a ring mounted on the shaft, said shaft and ring having intercommunicatin passages therein, said ring having universal coupling sockets spaced apart and facing toward each other at one'side of the ring and communicating with respective passages therein, a connector secured to the support and having a shank with openings therethrough leading from the conduits and terminating in oppositely facing universal coupling sockets, said shank of the connector extending with its sockets in substantially circumferential alinement with the respective coupling sockets cf the ring, and lengthwise expanding coupling members sprung into position between the sockets of the connector shank and the respective sockets of the ring to maintain intercommunication between the support and the ring during any relative movements therebetween.

4. In a fluid transmission connection, a supuniversal sockets at port having a pair of conduits therein, a shaft mounted to turn in the support, a ring mounted on the shaft, said ring having independent annular grooves therein and said shaft having radial openings independently communicating with the grooves of the ring, said ring also having radial projections spaced apart and provided with each other and communicating respectively with the grooves of the ring, a T-shape connector secured to the support and having a shank with independent passages therein opening into the conduits of the support and provided with universal sockets at the opposite sides of the shank near the end thereof, said shank extending into the space between the radial projections of the ring and being spaced intermediately thereof, normally expansible coupling elements disposed at opposite sides of the shank and having complemental universal fittings for frictional engagement in said sockets of the ring projections and the shank for absorbing circumferential radial and lateral vibrationbetween the support and the ring on the shaft, and anchoring means for connecting the ring to the shank of said T shape member to hold the ring from turning during rotation of theshaft.

LEONARD FREDERICK GEORGE BUTLER. WILLIAM CORDINER. I

their ends facing toward 

